Category: Swarm

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Magnitude 3.1 earthquake in Katla volcano this morning

Today at 08:26 UTC this morning a magnitude 3.1 earthquake took place in Katla volcano. There was minor pre-earthquake activity before the magnitude 3.1 earthquake took place, the depth of this earthquake was around 100 meters (0.1 km). There was also some minor aftershock activity following this earthquake. No change in harmonic tremor took place following this earthquake. So there is a good chance this was just part of normal autumn activity in Katla volcano. This earthquake activity did appear clearly on my geophone network. It can be viewed here on my geophone network web page.


The earthquake as it did appear on my geophone station in Skeiðflöt. This image is released under Creative Commons licence. See CC licence page for more details.


The earthquake as it did appear on my geophone station in Heklubyggð. This image is released under Creative Commons licence. See CC licence page for more details.


The location of the earthquake in Katla volcano. Copyright of this image belongs to Icelandic Meteorological Office.

More earthquakes like this should be expected in Katla volcano. But it is impossible to know if there is going to be an eruption in Katla volcano any time soon. But so far everything is quiet in Katla volcano. Besides occasional earthquake swarm that is taking place in Katla volcano.

Icelandic news about this earthquake activity

Jarðskjálfti í Kötlu – 3,2 að stærð (Rúv.is)
3,2 stiga skjálfti í Kötlu (mbl.is)
Snarpur skjálfti í Kötlu (Vísir.is)

Blog post updated at 19:34 UTC on 03.10.2012
Blog post updated at 05:45 UTC on 04.10.2012

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Earthquake activity east of Grímsey Island (TFZ). Possible fake earthquakes in Eyjafjallajökull volcano

At 03:03 UTC an earthquake with the early and unconfirmed magnitude of ML3.3 took place east of Grímsey Island. This earthquake did take place on TFZ. It is possible, but this earthquake might be the start of an earthquake swarm in this area. But that is not uncommon pattern for earthquakes in this area. But however it also happens that earthquakes like this one takes place. But then nothing more happens.


Earthquake activity in TFZ. The early magnitude ML3.3 earthquake is marked with a green star. Copyright of this image belongs to Icelandic Meteorological Office.

Eyjafjallajökull volcano

There has also been some earthquake activity in Eyjafjallajökull volcano during the night. This activity is possibly false due to weather or faulty SIL seismometer. The earthquake that have been detected so far have extremely low quality. But the increases the chance of them being false, rather then real events. It is not going to get known if this activity is real or not until it is reviewed by seismologist at Icelandic Meteorological Office.


The possible earthquake activity in Eyjafjallajökull volcano. This activity might be due to faulty hardware or weather, rather then real activity in Eyjafjallajökull volcano.Copyright of this image belongs to Icelandic Meteorological Office.

Eyjafjallajökull volcano has been quiet since it’s eruption in the year 2010. I do not expect that to change any time soon. Since it seem that Eyjafjallajökull volcano eruption cycle is around 150 to 500 year (theoretical maximum in my opinion). So I am not expecting anything to happen in Eyjafjallajökull volcano any time soon. If this earthquake activity is confirmed it is interesting. What might come out it is impossible to know for sure.

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Minor earthquake swarm in Katla volcano

Tonight around 22:30 UTC there was an minor earthquake swarm in Katla volcano. This earthquake swarm did last in about 20 minutes. After that the earthquake activity did drop back to normal background levels. This earthquake swarm is most likely part of normal autumn earthquake activity in Katla volcano. More earthquake swarms like this should be expected in Katla volcano during next few weeks.


Earthquake activity in Katla volcano this evening (28.09.2012). Copyright of this image belongs to Icelandic Meteorological Office.

What happens next is impossible to know. But I am not expecting anything special to happen in Katla volcano following this earthquake swarm. This earthquake swarm did appear clearly on my geophone at Skeiðflöt and Heklubyggð. The geophones can be viewed here.

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Minor earthquake swarm in Katla volcano

Normal autumn activity appears to be starting in Katla volcano. This earthquake activity is not something to be alarmed about. But worth keeping an eye on anyway.


The earthquake activity in Katla volcano during the past 48 hour period. Copyright of this image belongs to Icelandic Meteorological Office.

This is just normal autumn activity. As such it is not dangerous and does not mean anything. More earthquakes might happen in next few days to weeks.

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Earthquake activity drops in TFZ

During the past few hours earthquake activity in TFZ has dropped. This is not unusual. As earthquake activity in this area happens in swarms. Last earthquake swarm in this area where in the years 1996 and 2004. Those earthquake swarm lasted for several days and made several earthquakes with the magnitude 4. It is impossible to know how long activity is going last in this area. But since it has been ongoing for better part of current week (week 38). It might well be this activity is already over. But only time is going to tell what happens next. In current earthquake swarm. More then 500 earthquakes have been recorded so far.


The area of activity in TFZ. Stars mark earthquakes that are larger then magnitude 4 in size. But red dots show other earthquakes. The arrows show the fault movements in this area. It is from this news here on IMO web page. Copyright of this image belongs to Icelandic Meteorological Office.


The earthquake swarm as it looks during the past 48 hours. Copyright of this image belongs to Icelandic Meteorological Office.


The earthquakes on IMO tracker. It shows the magnitude of most of the earthquakes that have taken place during past 48 hours. Copyright of this image belongs to Icelandic Meteorological Office.

As sad before. It is impossible to know what happens next in this earthquake swarm. But it might well be that it is over by now. Only time is going to tell us what happens next in this. Chance of an larger earthquake taking place in this area remains high.

Almannavarnir announcement (Icelandic Civil Protection System)

Jarðskjálftahrina úti fyrir Norðurlandi (Almannavarnir.is, Icelandic)

Icelandic news about this earthquake swarm

Jarðskjálftar í Eyjafjarðarál (Icelandic, vedur.is)
Talsverð jarðskjálftavirkni á Norðurlandi (Icelandic, Vísir.is)
Fjórir skjálftar yfir 4 að stærð (Icelandic, mbl.is)
Íbúar geri ráðstafanir til að draga úr tjóni (Icelandic, mbl.is)

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TFZ earthquake swarm update at 20:50 UTC

This is a short update for the earthquake swarm in TFZ at 20:50 UTC.

At 19:42 UTC on 20.09.2012 an earthquake with the magnitude of ML4.2 took place on TFZ. This earthquake swarm was most likely felt in Siglufjöður town, Dalvík town and possibly more places around the epicenter of this earthquake. This earthquake did also appear clearly on my geophone network in Iceland. Swarm of smaller earthquakes did follow this larger earthquake as before.


The epicenter of the latest magnitude ML4.2 earthquake in TFZ. Copyright of this image belongs to Icelandic Meteorological Office.


The progress of the earthquake swarm during the past 48 hour period. This earthquake swarm happens in swarm, with drop in activity between them. Copyright of this image belongs to Icelandic Meteorological Office.


The earthquake swarm as it did appear on my Hvammstangi geophone station. This image is released under Creative Commons licence. Please see CC licence page for more details.


The earthquake swarm as it did appear on my Heklubyggð geophone station. This image is released under Creative Commons licence. Please see CC licence page for more details.

It is impossible to predict the progress and development of this earthquake swarm. But I expect this earthquake swarm to continue for the next few hours to days. It might last longer then few days. But only time is going to tell us what is going to happen next in this earthquake swarm. I am going to post new update on this earthquake swarm once I have had the time to check some of this data. But that might take few hours until I can do so. At the longest, not until tomorrow. Depending on IMO work on this earthquake swarm data. I am going to post new updates on this earthquake swarm soon as possible if anything major happens.

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Continued earthquake activity in TFZ

This morning (19.09.2012) at 04:53 UTC the earthquake swarm that has been ongoing in TFZ (Tjörnes Fracture Zone) started to intensify. But it was not until 07:55 UTC the first strong earthquake did happen. But then a magnitude 3.0 earthquake did take place about 20 km north-east of an town named Siglufjörður. The largest earthquakes have been felt in Siglufjörður, Ólafsfjörður and Sauðárkrókur and possibly more towns close to this area of activity on TFZ. The largest earthquake so far had the magnitude of ML4.3, other earthquakes had the magnitude 3.0, 3.4, 4.0 and 3.2. The depth of this earthquake swarm is from 17 km and up to 2 km or so. This area does not have any active volcanoes. But it highly active when it comes to earthquakes. But spreading in this area of Iceland is up to 50mm/year.


This image shows part of the Tjörnes Fracture Zone. It is from this science paper here. Copyright of this image belongs to Icelandic Meteorological Office/Hjorleifur Sveinbjornsson


Earthquake swarm at 15:10 UTC. As can be seen here on this image where the earthquake swarm is taking place. Copyright of this image belongs to Icelandic Meteorological Office.


The earthquake swarm at 16:15 UTC. This image has few new earthquakes that have taken place in this earthquake swarm since the picture from 15:10 UTC. Copyright of this image belongs to Icelandic Meteorological Office.


The earthquakes as they did appear on my Hvammstangi geophone. This image is released under Creative Commons Licence. Please see CC page fore more details.


The earthquakes as they did appear on my Heklubyggð geophone. This image is released under Creative Commons Licence. Please see CC page fore more details.


The magnitude ML3.0 earthquake on TFZ. This image is released under Creative Commons Licence. Please see CC page fore more details.


The magnitude ML3.0 earthquake on TFZ. This image is released under Creative Commons Licence. Please see CC page fore more details.


The magnitude ML4.3 earthquake on TFZ. This image is released under Creative Commons Licence. Please see CC page fore more details.


The magnitude ML4.3 earthquake on TFZ. This image is released under Creative Commons Licence. Please see CC page fore more details.


The magnitude ML4.3 earthquake on TFZ. This image is released under Creative Commons Licence. Please see CC page fore more details.


The magnitude ML4.0 earthquake on TFZ. This image is released under Creative Commons Licence. Please see CC page fore more details.


The magnitude ML4.0 earthquake on TFZ. This image is released under Creative Commons Licence. Please see CC page fore more details.


The magnitude ML4.0 earthquake on TFZ. This image is released under Creative Commons Licence. Please see CC page fore more details.

The last earthquake was at 16:52 UTC. That was magnitude 2.0 earthquake. But it is hard to know if this earthquake swarm is over or not. I am going update this blog post or make a new one if any new major development take place in TFZ. Larger earthquakes in this area cannot be ruled out at this time.

Icelandic news about this earthquake

Harðir jarðskjálftar fyrir norðan (mbl.is)
Skjálftahrina fyrir norðan (Vísir.is)
Jarðskjálfti 4,3 í Eyjafjarðarál (Rúv.is)
Enn skelfur undan Tröllaskaga (Rúv.is)

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Earthquake activity drops in El Hierro volcano

Earthquake activity in El Hierro volcano has started to drop off again. During the last 24 hour period there have only been something around 28 earthquakes. But earthquake activity did peak with 182 earthquakes during 24 hour period on Sunday 16. September 2012.


The earthquake activity in El Hierro volcano at 19:22 UTC. As can be seen here. Everything is quiet for now.Copyright of this image belongs to IGN.

It is hard to say what happens next in El Hierro volcano. But magma is still getting injected into El Hierro volcano at depth. Eruption is still an possibility while inflation continues at the rate it is going. There is always the chance that deflation is going to start in El Hierro volcano. Chance of an eruption in El Hierro volcano remains high. But when it might start it impossible to say at this point.

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Earthquake swarm between in Denmark and Sweden

Today (18.09.2012) at small earthquake swarm started in northern Denanmark, with the fault line extending upwards Sweden. The reason for earthquakes in this area is old fault lines. Along with the fact the Alps pressure the crust in Denmark (from what I did read long time ago). There is also glacier rebound taking place in Denmark and Sweden, along with Norway and Finland. The largest earthquakes in this swarm have had magnitude of ML2.4 and ML2.3. Both with depth of 1 km. But that might also be subject to change.


The area of the earthquake swarm. Some earthquakes might not have correct location. Copyright of this image belongs to EMSC.


The ML2.4 earthquake that took place at 16:30 UTC. Copyright of this image belongs to EMSC.


The ML2.3 earthquake that took place at 17:04 UTC. Copyright of this image belongs to EMSC.

The last earthquake that took place in this area was at 17:04 UTC. Since then no new earthquake have taken place. There might be some earthquakes later. But I find it unlikely to happen. But it hard to know for sure. But this is continental crust. So it moves slowly, when it moves at all in when it comes to earthquakes or other such changes. More earthquakes from this earthquake swarm can be found on EMSC web site.

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Earthquakes in Tindafjallajökull volcano

One of the most quiet volcanoes in Iceland had earthquake swarm today (17.09.2012). I am not aware of any major earthquake activity in Tindafjallajökull volcano during the past 20 years. I am not sure that if there has been any earthquake activity in Tindafjallajökull volcano during this time. One off-earthquake might have happened once in a while. As they do with every volcano in Iceland from time to time. It is unclear why this earthquake swarm took place. But this might be due to stress changes in the area. Rather then anything volcanic taking place in Tindafjallajökull volcano.


Activity in Tindafjallajökull volcano. Copyright of this image belongs to Icelandic Meteorological Office.

The largest earthquake in this swarm had the magnitude of 1.1. The depth of this earthquake swarm was from 10.7 km and up to 3.1 km. This earthquake swarm appears to be over by now.

Katla volcano

The image above also shows earthquake activity in Katla volcano. This earthquake activity is well below what did happen in May to end of July this summer (2012) in Katla volcano. Currently the activity in Katla volcano is low and has been so for many weeks now. I am not expecting that change without some increase in smaller earthquakes first. For the moment, everything is quiet in Katla volcano.